They arrived at the magnificent white marble monument to love – it was commissioned by the emperor in 1632 as a mausoleum to house his wife – on Saturday afternoon local time and paused to take in the wonder of the sight before them. "It's beautiful," William said, calling the historical site "stunning."
And in a moment that has been widely anticipated for months, Kate – in a white dress with blue accents by India designer Naeem Khan – and William stopped to take a seat on the bench made famous by William's late mother, Princess Diana, who famously visited India's most famous landmark in 1992.
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Kate, 34, followed her husband's lead in taking off her sunglasses before smiling warmly for the cameras.
Then just 30 years old, Diana posed for a photo that would later become iconic: In the famous photo, she cuts a solitary figure on the bench – later viewed by some as a sign of things to come when her separation from Prince Charles was announced a few months later.
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Their spokesman said, "They decided to sit on the bench this morning. It was not something they had properly considered until this morning. The decision for them was that is the place where people who come here to see this place will sit. It is a totally symmetrical position, right in the center
"That's the reason the Princess of Wales sat there when she came. It's the natural place. They made the decision on that basis."
But of course they were aware of the significance – as he said in his statement. "He completely understands that people come to visit this place with his mother in mind. It's about new memories for them."
In March, a palace spokesman addressed William's appreciation for the connection between India and his mother.
William is "of course aware of the huge esteem his mother, the late Princess of Wales, is held in India and he appreciates the iconic status of the images that exist of the Princess at the Taj," the spokesman said.
Adding that William and Kate were "looking forward to creating some new memories," the spokesman said, "He feels incredibly lucky to visit a place where his mother's memory is kept alive by so many who travel there."
Of course, there is a key difference between Diana's visit and her son and daughter-in-law's.
"William will remember, and I'm sure, understand, how difficult it must have been for his mother," her former bodyguard Ken Wharfe, who was present during Diana's stop at the Taj, tells PEOPLE.
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Wharfe, whose book Closely Guarded Secret chronicled his work with Diana, recalls her famous words at the photo call. "When Diana sat on that bench, she was asked, 'What does it feel like?' She turned to me and said, 'What shall I say, Ken?' So I just said quickly, 'Just say it is healing experience.' "
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"She confided in William a lot at that age," says Wharfe. "She will have said, 'This is an amazing place – one day I hope you do this, William. It is one of the seven wonders of the world and I was fortunate enough to go there.' She was never negative about her husband in his company, she never criticized her husband in his company. She certainly would have said all the positive things about somewhere they had been."
However, those close to the royal couple downplayed the link with Diana.
A source close to the couple said, "For the Duke of Cambridge, his mother's visit to the Taj Mahal is not a particularly strong memory at all.
"He has many other memories of his mother that are much more important to him. The visit was about creating new memories for their family."
The spectacular historical site served as the last major stop for the royal couple before they head home to reunite with their "massively" missed children, Prince George and Princess Charlotte.
Kate is bringing home at least one special souvenir: a necklace given to her by Queen Jetsun, which she paired with an Alexander McQueen upon leaving Bhutan Saturday morning.
Governor of Paro Chenko Tshering and education minister Norbu Wangchuk, who had greeted the couple when they arrived in Bhutan two days ago, were there to see them off from the country that prides itself on being the happiest in the world.
"I think our happiness index has shot up – this visit has been a blessing for Bhutan," said Wangchuck. "It is wonderful they got to meet our King and Queen and the new prince."
Tshering, who was with the couple at the Tiger's Nest monastery on Friday, added, "They loved the walk and were very fit. William got to see a yak which he said was a first.
"They're a marvelous couple and it's been an honor to receive them. The relationship between our King and Queen and the British people is a good one."